* pb: share the stale-socket tolerant unix listener
ServeGrpcOnLocalSocket already treats the local socket as optional; pull the remove-and-listen block out so the filer, s3, and sftp http sockets can use it too.
* command: keep filer, s3, and sftp up when the local socket cannot bind
A stale socket file owned by another uid (e.g. left in /tmp by a containerized job) made os.Remove fail with EPERM and the Fatalf took the whole server down. The gRPC local socket already treats the unix listener as optional; do the same for the http/sftp sockets.
* filer: clear shared localSocket flag when the unix socket cannot bind
s3.localFilerSocket and (in weed server) the sftp local socket share the
filer's -localSocket flag pointer. If the filer cannot bind the socket it
now keeps running without it, so consumers still holding the configured
path would dial a dead or foreign-owned socket.
* command: keep sftp on its own localSocket flag under weed server
sftpOptions.localSocket was overwritten with the filer's -localSocket
flag, so -sftp.localSocket was ignored and an explicit filer socket path
made the sftp server try to bind the same socket the filer already held.
* s3: fall back to TCP when the filer local socket cannot be dialed
The embedded S3 server copies the filer's -localSocket flag before the filer tries to bind it, so a socket that never comes up left every filer HTTP request dialing a dead path. Try the unix socket first and fall back to the request's TCP address on dial failure.
* filer: keep the shared localSocket flag read-only after startup
Clearing *fo.localSocket raced with the embedded s3 goroutine reading the same flag pointer and could not help a reader that had already copied it. The s3 filer client's TCP fallback covers the unbound-socket case without mutating shared flag state.
Chris Lu
cd97c93deb